At the present time the theft of automobiles (cars) from parking areas is an important problem. "Parking areas" include shopping malls, parking lots and other outdoor and indoor parking areas, indoor parking garages, airport parking lots and other paid and unpaid car parking facilities, gated communities (private communities) as well as military bases and other facilities where cars are parked.
Despite the best efforts of auto manufacturers, car theft device manufacturers and the police, car theft from parking areas remains as one of the most prevalent crimes, resulting in the loss of billions of dollars and high car theft insurance rates in many areas. In addition, customers may fear leaving their cars in shopping malls, and other parking lots, resulting in a loss of business to such malls.
Car manufacturers now produce cars with various anti-theft devices, such as locked steering wheels, keys with microprocessor chips, and remote control locks. In addition, various steering wheel locks and bars are widely used. Another anti-theft system uses a radio transmitter hidden in the car which is activated when the car is reported as being stolen. Despite these devices, car theft from parking areas is still a problem. For example, The New York Times, Feb. 6, 1996, pages B1,B4, reports that at the Green Acres shopping mall in Valley Stream, Long Island, N.Y., as a result of increased security, the number of cars stolen from that mall fell from 532 cars in 1984 to 159 cars in 1995, still an unacceptably large number.
When a car is stolen it may be reported to the police almost immediately. However, by that time it may be out of the parking area and on its way, for example, to be disassembled in a "chop shop" or shipped abroad. The police would be notified of the car's description, i.e., "a white 1995 Acura Legend four-door" and its license number, i.e., New York "JWB 123". However, the thief, to prevent being caught, may immediately, before he exits the parking area, switch the original license plates with license plates he has brought with him. Consequently, the police would not be able to detect and stop the stolen car even if they are present at the exit of the parking area when the thief drives out with the stolen car.
The issued U.S. patents mentioned below are incorporated by reference. U.S. Pat. No. 4,947,353 uses a scanning laser, which scans at 160 times per second, on one side of a roadway, and a vertical elongated photoelectric detector on the other side, to measure the heights of vehicles. U.S. Pat. No. 5,088,827 discloses a system for measuring the width of a traveling object, such as a wire, being manufactured. U.S. Pat. No. 5,083,200 relates to using a linear camera for obtaining the silhouette of a traveling vehicle to determine if it is a truck etc., using its length and height. U.S. Pat. No. 5,381,155 uses a license plate reader, a speed measuring device, a data base of registered vehicles and a variable message sign to display the names of speeding drivers on the sign. In U.S. Pat. No. 5,066,950 two spaced-apart infra-red beams are used to indicate the speed, length and separation of traveling vehicles for photographing speeding vehicles.
The following U.S. patents relate to reading license plates and generating digital signals representing the plate numbers: U.S. Pat. Nos. 4,567,609; 4,817,166; 5,081,685; 5,136,658; 5,175,617; 5,204,573; 5,204,675; 4,731,854; 4,878,248; 5,315,664; 5,425,018.